Motion translating means

ABSTRACT

The invention relates to actuating mechanism for moving switch contacts to thereby open and close a circuit in a vacuum envelope. The actuating mechanism includes an oscillatable lobe associated with pivotal lever means which when motivated cause the contacts in the vacuum envelope to open and close.

United States Patent lnventors Charles Andre Cichockie Edouard Mancini;Gustave Sutter, all of Petit-Lancy, Switzerland [51] Int. Cl ..l-l01h33/66 [50] Field of Search ZOO/144.2, 153.13,153.7

[56] References Cited UNITED STATES PATENTS 3,214,557 10/1965 Pflanz200/144(.2) 3,467,800 9/1969 Barr 200/144(12)X Primary ExaminerRobert S.Macon AttorntyEdwin E. Greigg ABSTRACT: The invention relates toactuating mechanism for moving switch contacts to thereby open and closea circuit in a vacuum envelope. The actuating mechanism includes anoscillatable lobe associated with pivotal lever means which whenmotivated cause the contacts in the vacuum envelope to open and close.

Appl. No. 830,347 Filed June 4, 1969 Patented June 1, 1971 AssigneeSociete Anonyme de Participations Appareillage Gardy Neuchatel,Switzerland Priority June 13, 1968 Switzerland 8803/68 MOTIONTRANSLATING MEANS 11 Claims, 2 Drawing Figs.

US. Cl ZOO/144b, 200/ 153LB PATENIEU JUN 1 l97| MOTION TRANSLATING MEANSThis invention relates to improvements in switches and, moreparticularly, to a lobe construction and actuating means therefor foropening and closing contacts in vacuum envelopes.

In electric switches there is now a tendency to use envelopes forcontact in vacuum. These envelopes comprise generally a hollow ceramicbody in which is positioned a stationary contact member and a movablecontact member. A high vacuum exists inside the envelope, and to ensurecomplete sealing of the inside of the envelope and of the movablecontact member against the outside, use if made of an extensible metaltube, called a boa, a bellows-type breathing tube. The path of movementof the movable piece is relatively short, generally less than mm.

Devices of this general type are well known and by way of example, seethe disclosure in the US. Pat. to Peek et al. No. 3,209,101, issuedSept. 28, 1965, which clearly shows means for operation of the circuitbreakers in vacuum envelope-type switches on which this invention is afurther improvement.

These vacuum envelopes are very advantageous because of their ability tomaintain excellent closure of the electric circuit. However, they arevery delicate and their lifetime is limited by the lifetime of thebellows-type breathing tube. These envelopes also become defective byimpact of the contacting surfaces against each other.

The invention has for its principal object a circuit breaking devicecomprising at least one envelope for making contact in vacuum comprisinga movable contact control piece and an actuating mechanism for suchpiece. The device is characterized in that the actuating mechanism forcontrol of the movable piece operates in two phases, the first phaseassuring the displacement of the mobile piece to form the contact, andthe second phase applying to such piece a predetermined force to assurethe pressure necessary to provide good contact and to eliminaterebounding of the movable contact.

Another object of the invention is to provide an improved actuating lobemeans which is rotatably mounted and arranged so as to transmit pressurethrough a lever means to open and close the contact elements.

A further object of the invention is to provide an organization ofelements, the assembly of which achieves a unique apparatus capable ofactuating a multiplicity of envelopes in series.

A still further object of the invention is to provide a constructionwhich enables the contact members to be brought into engagement at sucha finely controlled speed that rebounding of the contact members iseliminated.

Yet another object of the invention is to provide a construction whichwill prolong the mechanical life of the vacuum envelopes as well as bemore economical to produce.

Further objects and advantages of the invention will become moreapparent upon a reading of the following detailed specification taken inconjunction with the drawing, in which:

FIG. 1 is a horizontal elevation of the new switch, partly broken away,comprising two vacuum envelopes connected in series and FIG. 2 is anenlarged view of the control mechanism for actuating the circuitbreakers within the vacuum envelopes of the electric switch mechanism.

Turning now to the drawing, the electric switch shown in FIG. 1 includesa base 1 on which is mounted a housing 2 of insulation material which isadapted to support two horizontally disposed vacuum envelopes 3, 3.These ampules are positioned in longitudinal alignment with each otherand are attached by means of their proximate ends to a bracket 4 whichis, in turn, mounted on top of the housing 2.

Each vacuum envelope carries a fixed contact member 5, 5' arranged toextend through the bottom of the envelope for purposes which will beknown to those skilled in the art. The movable members which carry thecircuit breakers (not shown) provided within the envelopes terminate inheaded stems 6,6 positioned in alignment with each other.

As can be best seen in FIG. 2, the stems 6, 6', which are associatedwith the circuit breakers (not shown), are acted upon by springs 7, 7seated with one end against the adjacent envelope and with the other endagainst a collar 8, 8' provided adjacent the end of each stem. Thesprings 7, 7' urge the mobile contact pieces into circuit breakingpositions, namely by keeping the movable circuit breaker contact piecesaway from the fixed contact pieces therefore.

The control apparatus which effects the movements of the mobile piecescomprises for each envelope a lever l0, l0 pivoted at one of its ends toa perforated piece ll, 11'. These two last-mentioned perforated piecesare slidably mounted on a rod 12 which is fixed at its opposite ends tothe bracket 4. A spring element 13 composed of a collection of resilientrings, well known as Belleville springs, urges the pieces II and 11 awayfrom each other and toward stop collars l4, 14' on the rod 12.

Each lever l0, 10' carries a roller l5, 15' which is posi tioned so asto engage the head of a plunger 16, 16 screwed into the control stem 6,6 of the movable member of each vacuum envelope.

The lower extremity of each lever 10, 10' carries a roller l7, 17 forcooperation with two other rollers l8, 18' which are mounted on alobe-shaped member 19 which is rotatable about an axis shownschematically at 20 with the supporting shaft forming the axis beingmounted in bore holes (not shown) in housing 2. The lobelike piece 19 bedisplaced angularly about by means of a control member 21 which extendsup into the housing 2, said member being connected to any kind of anactuator means.

When the lobe-shaped member 19 is rotated, the rollers l8, l8 displacethe rollers 17, 17' and with them the lower ends oflevers I0, 10. Afterthe member 19 has turned 90, the centers of the rollers l7, l7, l8 and18' are in substantial horizontal alignment with one another and thelower ends of levers 10, 10 are thereby separated a maximum distancefrom each other.

The expansive force of the Belleville spring component 13 is greaterthan the force that is required for displacing each of the stems 6, 6'and to compress the springs 7, 7. The result will be that duringrotation of the member 19, the upper ends of levers l0, 10 will remainin the same position shown in FIG. 2, while the stems 6, 6 are movedfarther away from each other to bring the movable circuit breakermembers of the vacuum envelopes into engagement with their respectivefixed contact members. Closure of the movable contact pieces of thecircuit breaker is obtained slightly before the end of the rotation ofmember 1?. From the instant when circuit closure occurs, the stems 6 and6' are not longer able to move still farther away from each other. Sincethe member 19 terminates its rotation and increases slightly farther theseparation of rollers l7, 17' from each other, the final degree ofincrement of such rotation will compress the spring 13. It will beapparent that the force which the spring 13 exerts upon the ends of armsl0, I0 is transmitted to the heads provided on stems 6 and 6'. The forceof spring 13 is indeed increased in proportion to the relative lengthsof the lever arms to rollers 17, 17.

When the circuit making contacts are to be opened within the envelope,the member 19 is moved in the opposite direction to return to theposition indicated in FIG. 2, and the stems 6, 6' are returned by theirsprings 7 and 7 to their initial positions to ensure opening of thecontacts. A slot 9 is provided in the control member 21 in such aposition that the speed of opening of the contacts will not depend onthe speed of movement of the member 21. The circuit can therefore beinterrupted manually without any special precautions.

It should be stated that the mechanism described above works in twophases. The first phase includes the rotation of the member 19 up to theinstant when the circuit making contacts are closed inside the vacuumenvelopes. During this first phase the displacement of stems 6, 6 iseffected at a controlled rate which slows down until closure is effectedsince the movement of rollers l7, 17 is limited by the rotation of themember 19 in accordance with a pseudo sinusoidal function. During thisfirst phase the circuit making contact pieces are moved toward eachother by relatively weak forces until they come into actual closedcontact.

In the second phase, which commences at the instant when the contactsclose, the contact pressure is applied progressive ly to the vacuumenvelopes during the last portion of the rotation of member 19. Sincethe spring 13 is very strong, the contact pressure provided for thevacuum envelopes is already obtained after only a slight movement of thepieces 11 and ll toward each other. This means that the application ofthe contact pressure commences almost immediately after the controlmembers move out of their dead center positions. The result will be thatat the instant of closure of the contacts, the speed at which thecontact members approach each other is very slow and is in phase withthe retardation. In this manner all rebounding of the contact membersfrom each other will be avoided and there will be a minimum accumulationof metallic powder. This arrangement makes it possible to avoid allhammering of the contacting circuit making and breaking members and allpremature separation of metallic dust as a result of arcing of thecontacts. Experiments have shown that the control mechanism describedgreatly prolongs the mechanical life of the vacuum envelopes.

As far as insulation from the ground is concerned, it can be realizedvery simply by using a control member 21 of insulating material.insulation can also be obtained by forming the levers l0, of reinforcedepoxy resin. Such a construction is very advantageous because the shaftcould then be grounded and could carry several actuator members 19 toactuate several circuit breakers, each comprising one or two vacuumenvelopes. These circuit breakers can then be used to opensimultaneously the different phases of a polyphasc circuit, or can beconnected in series to break in one phase a higher voltage than thatwhich corresponds to the maximum voltage to be broken by two envelopesin series. It is therefore possible to combine these two possibilitiesand to obtain a unique apparatus comprising, for example, six envelopesin series for each phase of a three-phase circuit, by providing on theshaft 20 nine members such as that illustrated at 19, each controllingtwo envelopes of the kind described above.

It is indeed possible to provide many variants of the above describedapparatus. Especially where only a single vacuum envelope is used, oneof the levers 10 or 10 can be omitted. The control mechanism can alsoassume other forms and in particular articulated mechanisms areespecially convenient because they also have a dead center.

It is also not absolutely necessary to use a dead center at all. Themovable contact circuit member of the vacuum envelope can also be actedupon by a mechanism exerting an increasing force upon the movable piecesfrom the beginning of the closure movement, the velocity of closing ofthis piece being, however, controlled by a suitable mechanism, forexample, by a hydraulic shock absorber. in this manner, the displacementof the movable piece occurs at a controlled speed, and the contactpressure would not be applied to the movable piece until after thecontact has been closed. The same result could also be produced by ahydraulic mechanism for controlling the movable piece, as by connectinga control piston which actuates the movable piece, with a chamber thatis under the required hydraulic pressure. However, this connectionshould be obtained by means of a passageway that is calibrated to limitthe speed of the piston at the time of its closing movement and makingit possible then to control the speed of closing of the movable member.

We claim:

1. An electric circuit-making and -breaking apparatus comprising a fixedcontact and at least one movable contact for operation in vacuumenvelope and having an open and a closed position, a two-step workingmechanism for actuation of said movable contact, said mechanismcomprising plural lever means and associated rotatable lobe meansarranged upon rotation to produce a decrease in the speed of the movable contact by limited movement of said lever means in a first directionduring said first step, said mechanism further includ ingpressure-limiting means for limiting the pressure applied to saidmovable contact when it is brought into closed position with the fixedcontact at the end of said first step, whereby rebound of said contactis avoided, the second step mechanism also including pressure-increasingmeans after ini' tial contact is made between the fixed and movablecontacts by moving the levers in a second direction to increase thepressure applied to said movable contact until the nominal contactpressure is obtained.

2. An electric circuit-making and -breaking apparatus as claimed inclaim 1, wherein plural envelopes are arranged to be operated in series.

3. An electric circuit-making and -breaking apparatus as claimed inclaim 1, wherein a plurality of roller means are affixcd to said levermeans.

4. An electric circuit-making and -breaking apparatus as claimed inclaim 3, wherein at least one of said roller means is arranged tocooperate with said movable contact.

5. An electric circuit-making and -breaking apparatus as claimed inclaim 3, wherein the lobe element includes roller means arranged tocooperate with the roller means on said levers, said lobe carried rollermeans being arranged upon rotation to move said levers in oppositedirections.

6. An electric circuit-making and breaking apparatus as claimed in claimI, wherein plural resilient means cooperate with said lever means andthe other of said roller means is in constant rolling contact with meanson said lobe.

7. An electric circuit-making and -breaking apparatus comprising a fixedcontact and a movable contact each of which lies in a fixed plane and isarranged for operation in a vacuum envelope and has an open and closedposition, a two step working mechanism for actuation of said movablecontact, said mechanism including plural levers a portion of each ofwhich intersects the plane of said contacts and which also includeportions extending therebeyond that are relatively fixed in spacedrelation while being adjustably interconnected one to the other, theother terminal end portions of said levers including means to cooperatewith means carried by a rotatable lobe element, means for rotating saidlobe in a first step to initially urge said levers away from each otherand to bring said contacts into initial engagement, said last-namedmeans upon movement to its second step of rotation thereby forciblyurging the contacts into tighter engagement.

8. An electric circuit-making and -breaking apparatus as claimed inclaimed 7, wherein the portions of the levers that are adjustablyinterconnected are maintained in spaced relation by resilient means.

9. An electric circuit-making and -breaking apparatus as claimed inclaim 7, wherein said vacuum envelope further includes an axiallydisposed fixed contact member arranged to extend beyond the confinesthereof.

10. An electric circuit-making and -breaking apparatus as claimed inclaim 8, wherein during the second step of rotation of said lobe elementthe resilient means which maintains the levers in spaced relation iscompressed.

11. An electric circuit-making and -breaking apparatus as claimed inclaim 8, wherein the resilient means consists of a Belleville spring.

1. An electric circuit-making and -breaking apparatus comprising a fixedcontact and at least one movable contact for operation in vacuumenvelope and having an open and a closed position, a twostep workingmechanism for actuation of said movable contact, said mechanismcomprising plural lever means and associated rotatable lobe meansarranged upon rotation to produce a decrease in the speed of the movablecontact by limited movement of said lever means in a first directionduring said first step, said mechanism further includingpressure-limiting means for limiting the pressure applied to saidmovable contact when it is brought into closed position with the fixedcontact at the end of said first step, whereby rebound of said contactis avoided, the second step mechanism also including pressure-increasingmeans after initial contact is made between the fixed and movablecontacts by moving the levers in a second direction to increase thepressure applied to said movable contact until the nominal contactpressure is obtained.
 2. An electric circuit-making and -breakingapparatus as claimed in claim 1, wherein plural envelopes are arrangedto be operated in series.
 3. An electric circuit-making and -breakingapparatus as claimed in claim 1, wherein a plurality of roller means areaffixed to said lever means.
 4. An electric circuit-making and -breakingapparatus as claimed in claim 3, wherein at least one of said rollermeans is arranged to cooperate with said movable contact.
 5. An electriccircuit-making and -breaking apparatus as claimed in claim 3, whereinthe lobe element includes roller means arranged to cooperate with theroller means on said levers, said lobe carried roller means beingarranged upon rotation to move said levers in opposite directions.
 6. Anelectric circuit-making and -breaking apparatus as claimed in claim 1,wherein plural resilient means cooperate with said lever means and theother of said roller means is in constant rolling contact with means onsaid lobe.
 7. An electric circuit-making and -breaking apparatuscomprising a fixed contact and a movable contact each of which lies in afixed plane and is arranged for operation in a vacuum envelope and hasan open and closed position, a two step working mechanism for actuationof said movable contact, said mechanism including plural levers aportion of each of which intersects the plane of said contacts and whichalso include portions extending therebeyond that are relatively fixed inspaced relation while being adjustably interconnected one to the other,the other terminal end portions of said levers including means tocooperate with means carried by a rotatable lobe element, means forrotating said lobe in a first step to initially urge said levers awayfrom each other and to bring said contacts into initial engagement, saidlast-named means upon movement to its second step of rotation therebyforcibly urging the contacts into tighter engagement.
 8. An electriccircuit-making and -breaking apparatus as claimed in claimed 7, whereinthe portions of the levers that are adjustably interconnected aremaintained in spaced relation by resilient means.
 9. An electriccircuit-making and -breaking apparatus as claimed in claim 7, whereinsaid vacuum envelope further includes an axially disposed fixed contactmember arranged to extend beyond the confines thereof.
 10. An electriccircuit-making and -breaking apparatus as claimed in claim 8, whereinduring the second step of rotation of said lobe element the resilientmeans which maintains the levers in spaced relation is compressed. 11.An electric circuit-making and -breaking apparatus as claimed in claim8, wherein the resilient means consists of a Belleville spring.